Deputy impeller power seal: vice impeller seal the use of the impeller and the series of vice impeller generated by the pressure seal, packing or lip sealing ring as a parking seal. In the pump inlet pressure value is not greater than the pump outlet pressure value of 10% single or multi-stage pump series of the first pump, can be used in this seal. It can operate without shaft seal water, diluted slurry, features good sealing effect etc.. But will increase the power consumption (generally need to increase the shaft power of 5% or so). Packing seal is a common seal form, applicable to all kinds of working conditions, matching PTFE packing, graphite packing, such as special materials can be used in corrosive or high temperature conditions. Has the advantages of simple structure, convenient maintenance, etc..